When Mayor Bill de Blasio’s administration unveiled a promotional video this summer in its bid to lure the Democratic National Convention to Brooklyn in 2016, most viewers saw a slick, breezy collage of a pulsing New York City — schoolchildren and Citi Bikes, culinary wonders and brochure-worthy parks.

Veterans of the previous administration saw something else: a rare, if silent, affirmation of the Bloomberg age from the successors who sharply criticize it.

The relationship between successive administrations is rarely uncomplicated. Perceived digs fester. Legacies wax and wane. And that magic date — the point at which a mayor is expected to cease criticisms of his predecessor — is never universally agreed upon.

Yet in the more than eight months since Mr. de Blasio’s inauguration — an event at which a number of speakers, though not Mr. de Blasio, assailed Mr. Bloomberg — an entirely peaceful transfer of power has proved particularly elusive.

After a stinging critique of Mr. Bloomberg’s tenure helped propel Mr. de Blasio, a Democrat, to victory last year, the mayor and his surrogates have continued to issue barbs at times, while appearing less eager to highlight Mr. Bloomberg’s contributions to some well-regarded policies that have been continued or expanded.

In recent weeks, as Mr. Bloomberg’s reign has drawn withering criticism over the handling of disaster relief after Hurricane Sandy and oversight at the Rikers Island jail complex, among other issues, former Bloomberg administration officials have increasingly moved to defend their former — and, in many cases, current — boss.

Since mid-August, four of the six news items posted on Mr. Bloomberg’s website have been testimonials to his record written by Mr. Wolfson, former Schools Chancellor Dennis M. Walcott or another former deputy mayor, Caswell F. Holloway. (Mr. Holloway was responding to a report in The New York Times about rebuilding after Hurricane Sandy.)

Aides to Mr. Bloomberg, a political independent, have not attacked Mr. de Blasio, but say it is their responsibility to correct the record when the mayor or his supporters misrepresent it.

“We’ve been surprised the extent to which it’s been necessary,” Mr. Wolfson said.

Administration officials have come to expect resistance from foes old and new on certain policies. As Capital New York reported, some education reform advocates have for weeks peppered reporters with opposition research on Mr. de Blasio’s prekindergarten program.

But the more frequent public defenses of Mr. Bloomberg from his own staff represent a new front.

In a statement, Mr. Ragone said, “Anyone who has worked here at City Hall should know that if you want to run an effective government, you just call ’em like you see ’em and move on to fixing the problems.”

“You just don’t have time for petty political skirmishes,” he added.

Many jabs at Mr. Bloomberg this year have touched on prominent campaign themes, like income inequality and the stop-and-frisk policing tactics — an issue that Police Commissioner William J. Bratton said in January had “more or less” been solved, noting that stops had fallen precipitously during Mr. Bloomberg’s final years in office. (The figure has continued to drop in areas across the city this year.)

The administration has lamented the unresolved labor contracts under Mr. Bloomberg. It has referred less often to the surplus that left Mr. de Blasio “in very good shape for his first budget,” said Carol Kellermann, the president of the Citizens Budget Commission.

Earlier this month, Mr. de Blasio criticized the Bloomberg administration’s Hurricane Sandy relief plans as lacking “a focus on real human beings.” Days later, he issued an announcement celebrating the city’s new “.nyc” websites — championed by Mr. Bloomberg and Christine C. Quinn, the former City Council speaker who ran against Mr. de Blasio in the Democratic primary for mayor last year — without mentioning either of them.

On housing policy, where Mr. de Blasio has spoken of a significant break from the Bloomberg years, the new administration has also strained to identify differences on some projects. At a groundbreaking in April for the first phase of an affordable housing development in East New York, Brooklyn, Mr. de Blasio said he planned to count 278 units from the complex, negotiated under Mr. Bloomberg, toward his goal of 200,000 affordable units in 10 years.

“The things that we put our hands on and help to achieve, we are counting,” Mr. de Blasio said then.

Asked at the same event whether there were significant differences between the terms negotiated at the complex by the last administration and the final plan, Mr. de Blasio’s deputy mayor for housing and economic development, Alicia Glen, said no.

Mr. de Blasio has been quick to praise Mr. Bloomberg’s record on issues like public health, and some administration officials, including Ms. Glen and Polly Trottenberg, the transportation commissioner, have often taken pains to credit their predecessors.

Some subjects have required a careful touch. Last month, after elementary- and middle-school students posted modest increases in test scores on statewide math exams, Mr. de Blasio emphasized that his approach would place less of a focus on the results of standardized tests, but credited the previous administration’s contributions to the gains. (“V classy,” Mr. Wolfson wrote on Twitter at the time.)

On occasion, Mr. de Blasio has cast blame on Mr. Bloomberg only to then castigate himself. Delays in installing security cameras in public housing were “unacceptable in the previous administration,” he said in June, and “unacceptable in my administration.”

And while Mr. de Blasio himself did not criticize Mr. Bloomberg on Inauguration Day, other speakers harshly condemned City Hall’s departing tenant. Among them was the singer Harry Belafonte, who suggested that Mr. Bloomberg was in part to blame for the nation’s “deeply Dickensian justice system.” A pastor likened the city to a “plantation.” Mr. de Blasio said afterward that he was “very comfortable with all that was done” at the ceremony.

Chafing at a City Hall successor’s remarks — much like assuming credit for policies that take effect on one’s watch — is a rich local political tradition. Defenders of Mayor David N. Dinkins, a Democrat, have long smarted over the criticisms from Mayor Rudolph W. Giuliani, a Republican, who, they say, never properly credited Mr. Dinkins with helping to drive down crime by adding to the police force and for his role in improving Times Square.

Then there was Mayor Edward I. Koch. Marveling in 2012 at the decision to rename the Queensboro Bridge in his honor, Mr. Koch recalled that he was less gracious to his predecessor, Abraham D. Beame, a fellow Democrat. “I never did a thing for Abe Beame,” he said, adding an expletive.

Mr. Bloomberg himself, who pledged to refrain from criticizing Mr. de Blasio after leaving office, has largely kept his promise.

Mr. Wolfson recalled a recent rebuke from the de Blasio administration — he said he could not remember which — that prompted him to approach Mr. Bloomberg’s desk at his foundation.

“I’m going to go after them,” Mr. Wolfson said of the current regime.

No, Mr. Bloomberg said, you are not.

“If I do it, will you fire me?” Mr. Wolfson asked, half-jokingly.

“Don’t test me,” Mr. Bloomberg deadpanned.

A version of this article appears in print on , on Page A1 of the New York edition with the headline: Ex-Mayor Is Scorned (and Affirmed) at City Hall. Order Reprints | Today’s Paper | Subscribe